1. Field of the Invention
The present invention relates to an insertion/extraction force reducing connector which can reduce manipulation force that is necessary in inserting or pulling one connector housing into or out of the other.
2. Description of the Related Art
In connectors used in connection portions of vehicle wire harnesses, the number of terminals of a connector is increasing as vehicles are coming to be equipped with more electric devices. And the manipulation force that is necessary in inserting or pulling one connector housing of a connector into or out of the other is increasing accordingly.
Increased manipulation force not only makes difficult a manipulation of inserting or pulling one connector housing of a connector into or out of the other but also may cause a fitting failure or the like of connected connector housings.
Therefore, multi-terminal connectors are desired to be insertion/extraction force reducing connectors (low insertion force connectors) which can reduce manipulation force that is necessary in inserting or pulling one connector housing into or out of the other. Various lever connectors have been proposed as insertion/extraction force reducing connectors.
Lever connectors are connectors in which a fitting manipulation lever which, when rotated, causes forces in the insertion/extraction direction to act on a pair of connector housings to be fitted with and connected to each other is provided between the pair of connector housings. Through leverage, the fitting manipulation lever can reduce manipulation force that is necessary in inserting or pulling one connector housing into or out of the other.
However, to reduce the manipulation force to a large extent in lever connectors, it is necessary to use a large fitting manipulation lever having a large leverage ratio. The use of a large fitting manipulation lever raises a problem that the size of the connector is increased.
In view of the above, an insertion/extraction force reducing connector 100 shown in FIG. 30 has been proposed which reduces manipulation force that is necessary in inserting or pulling one connector housing into or out of the other without using a fitting manipulation lever (refer to the following Japanese Patent No. 2,671,729).
The insertion/extraction force reducing connector 100 is composed of a first connector housing 110 and a second connector housing 120 to be connected to the former.
The first connector housing 110 is equipped with a first terminal holding part 112 which holds plural first terminal metal fittings 111 and a cylindrical hood part 113 which extends from a front outer circumferential portion of the first terminal holding part 112 and is to be fitted with and connected to the second connector housing 120.
The first terminal metal fittings 111 which are held by the first terminal holding part 112 are tongue-shaped male terminal metal fittings (tab terminal metal fittings).
The second connector housing 120 holds plural second terminal metal fittings (not shown) to be fitted with and connected to the respective first terminal metal fittings 111 of the first connector housing 110 in such a manner that they are divided into two groups, that is, a first group and a second group. The second terminal metal fittings are fitted with and connected to the first terminal metal fittings 111 of the first connector housing 110 by fitting a front portion of the second connector housing 120 into the hood part 113 of the first connector housing 110.
The second connector housing 120 used in Japanese Patent No. 2,671,729 is equipped with an outer housing 124 and an inner housing 126. The outer housing 124 has a first group terminal holding part 123 which houses and holds the second terminal metal fittings belonging to the first group, and is to be fitted into the hood part 113. The inner housing 126 has a second group terminal holding part 125 which houses and holds the second terminal metal fittings belonging to the second group, and is attached to the outer housing 124.
The outer housing 124 has, adjacent to the first group terminal holding part 123, an inner housing space 124a in which the inner housing 126 is inserted for attachment.
In the inner housing 126, the second group terminal holding part 125 is temporarily locked in the outer housing 124 (placed in the inner housing space 124a) in such a manner that the second group terminal holding part 125 project from the level of the first group terminal holding part 123. Therefore, when the second connector housing 120 is fitted into the first connector housing 110, the second terminal metal fittings that are held by the second group terminal holding part 125 are fitted with and connected to the associated ones of first terminal metal fittings 111 of the first connector housing 110 earlier than those held by the first group terminal holding part 123 are.
When the second terminal metal fittings which are held by the second group terminal holding part 125 have been completely fitted with and connected to the associated ones of first terminal metal fittings 111 of the first connector housing 110, the temporary lock state of the inner housing 126 is canceled, whereupon the tip surface of the second group terminal holding part 125 is allowed to retract to such a position as to be flush with the tip surface of the first group terminal holding part 123. As the inner housing 126 retracts, fitting of the second terminal metal fittings that are held by the first group terminal holding part 123 with the associated ones of the first terminal metal fittings 111 of the first connector housing 110 proceeds.
In the insertion/extraction force reducing connector 100 disclosed in Japanese Patent No. 2,671,729, the second terminal metal fittings that are held by the second connector housing 120 are divided into two groups and are fitted in order on a group-by-group basis. In this manner, the manipulation force that is necessary in fitting one connector housing to or with the other is reduced.
Since no fitting manipulation lever is used for a manipulation for fitting one connector housing to or with the other, the size of the connector can be reduced.
However, in the insertion/extraction force reducing connector disclosed in Japanese Patent No. 2,671,729, the second connector housing 120 is configured in such a manner that the inner housing 126 is inserted in and attached to the outer housing 124. The outer housing 124 has an outside wall 124b with which the entire outer circumferential surface of the inner housing 126 is covered, the outside wall 124b causes increase in volume and weight. This raises a problem that the size and the weight cannot be reduced very much from conventional lever connectors.